摘要:
An image forming apparatus and an image forming method thereof are provided. An image forming apparatus according to an exemplary embodiment of the present general inventive concept comprises a decoder to decode a compressed image to convert the compressed image into image data, a pure black determining unit to determine whether the image data is pure black by using information of the converted image data, a section classifying unit to classify the image data into a text section and an image section by using a result of the pure black determination, and a color coordinate converter to perform color coordinate conversion on the image section of the classified sections. Therefore, it is possible to improve readability of black text.
摘要:
A printing method, and an image forming apparatus and image forming system to perform the method, the method including performing a multi-bit halftoning of a pixel of image data if the pixel is to be printed with a dark developer, performing a single-bit halftoning of the pixel if the pixel is to be printed with a light developer, and printing the halftoned image data.
摘要:
An image forming apparatus and an image forming method thereof are provided. An image forming apparatus according to an exemplary embodiment of the present general inventive concept comprises a decoder to decode a compressed image to convert the compressed image into image data, a pure black determining unit to determine whether the image data is pure black by using information of the converted image data, a section classifying unit to classify the image data into a text section and an image section by using a result of the pure black determination, and a color coordinate converter to perform color coordinate conversion on the image section of the classified sections. Therefore, it is possible to improve readability of black text.
摘要:
An error diffusion processing method includes determining a binary value of an input pixel according to a grayscale level of the input pixel, searching a nearest pixel that has the same binary value as the input pixel, and comparing a measured actual distance with an ideal distance between the two pixels, so as to compute a first adjustment value. By applying a noise array to an input image, a second adjustment value is also computed according to a noise value of the input pixel. Based on the first and second adjustment values, a threshold is adjusted to determine the binary value of the input pixel. The adjusted threshold is compared with the grayscale level of the input pixel, and according to the comparison result, the binary value of the input pixel is determined. By diffusing an error value, which is a difference between the grayscale level and the determined binary value of the input pixel, to neighboring pixels, the grayscale level of the neighboring pixels is changed. A third adjustment value is also applied to reduce a diagonal pattern due to binarization of the input pixel, while encouraging a perpendicular pattern.
摘要:
Provided are a method and apparatus for determining error diffusion coefficients. The method includes: (a) setting N groups of error diffusion coefficients (N is a positive integer), in which each group includes a plurality of coefficients; (b) binarizing an image having one gray level value using each of the N groups of error diffusion coefficients; (c) detecting N fit values with respect to N binary-coded images using an evaluation function; (d) determining whether the fit values are detected a predetermined number of times; (e) when a detection number of the fit values does not coincide with the predetermined number of times, reproducing the N groups of error diffusion coefficients according to reproduction rates determined by the N fit values; (f) selecting optional error diffusion coefficients in the reproduced N groups of error diffusion coefficients, and substituting portions of data of selected error diffusion coefficients with each other; and (g) determining the N groups of error diffusion coefficients including the error diffusion coefficients containing substituted data as new error diffusion coefficients, and returning to step (b).
摘要:
An image forming apparatus which provides a plurality of developers that have different densities for each color, and an image forming method thereof. The image forming method may include detecting a remaining amount of a first developer; and forming an image by expressing a gray scale of inputted data according to a multi-bit halftoning process using a second developer that is similar to the first developer in color and higher than the first developer in density if the remaining amount of the first developer is a preset value or less.
摘要:
An image processing method and an image forming apparatus using the same. The method of processing includes dividing an image into a predetermined number of blocks, calculating an average of color signals of pixels existing in each of the blocks divided, classifying the blocks into color blocks and monochrome blocks using the calculated average, and determining whether the image is a color image or a monochrome image using a proportion of the color blocks. Accordingly, for a document wherein color and monochrome images are mixed, it is automatically determined whether an image is a color image or a monochrome image.
摘要:
A method and apparatus are provided for compensating for the degradation of a print image due to a malfunctioning nozzle that irregularly ejects ink. A malfunctioning nozzle is detected among nozzles installed in an inkjet image forming apparatus, and image data of a print position adjacent to a compensation position printed by the malfunctioning nozzle is exchanged for image data of a print position in an interest or inspection region near the compensation position. Accordingly, degradation of print quality, such as, for example, an unintended visible white band, can be prevented and the lifetime of the printhead can be lengthened.
摘要:
Disclosed is an error diffusion apparatus with cluster dot. The error diffusion apparatus for performing an error diffusion on a second pixel based on a first pixel includes: a binary processing unit for binarizing a tone value of the first pixel based on a predetermined threshold; a binary error diffusion unit for computing a binary error value based on a difference between the tone value of the first pixel and a binary tone value for the first pixel, and reflecting the binary error value on a tone value of the second pixel applied to the binary processing unit; and a cluster forming unit for deciding whether to form a cluster for the first and second pixels, in reference to a predetermined cluster pattern and a binary tone value of the first pixel. The error diffusing apparatus reduces switching noises generated from the image forming process in pixel unit, and expands the tone value range of an image. In addition, the error diffusing apparatus prevents deteriorations in image quality by limiting the cluster size and restricting the cluster formation in the shadow and highlight areas of an image.
摘要:
An error diffusion method and apparatus using an area ratio of candidate colors in a CMYKRGBW cube, wherein the candidate colors are determined in response to an input value, and the CMYKRGBW cube is converted into a color space consisting of only four colors so that the candidate colors can be evenly distributed. The color space is then expressed using the area ratio of the candidate colors. Accordingly, it is possible to evenly distribute candidate colors in all gray-scale regions, including a highlight region, thereby obtaining a soft image that does not have a pattern that is strenuous on the eye of an observer.